Hydraulic transmission



Oct. 22, 1940. J. A. SHULTZ 2,218,896

HYDRAULIC TRANSMISSION Filed Nov. 30. 1939 4 She ets-Sheet 1 :ETg

Inventor A itorneys 0a. 22. 1940. v A. HULT-z 2,218,896

HYDRAULIC TRANSMISS ION Filed Nov. 30, 1939 4 Sheets-Sheet 3 JESSE A. SHUL T2,

A iiorneys Inventor Oct. 22, 1940. J A, SHULTZ 2,218,896

HYDRAULIC TRANSMISSION Filed Nov. 30, 1939 4 Sheets-Sheet 4 lnventor JESSE A. fiHz/Lrz,

Patented Oct. 22, 1940 UNITED ,sTArEs PATENT o -Fms 2,218,896 HYDR ULIC TRANSMISSION Jesse Albert Shultz, st. Joseph, Mo.

Application November,30,-1939, Serial No. 306,995

2 Claims.

The present inventionrelates to new and useful improvements in hydraulic transmissions particularly for motor vehicles but it will be understood, of course, that the device may be used for any other purpose for which it may be found adapted and desirable.

The primary object of the invention is to provide, in a manner, as hereinafter set forth, .a hydraulic transmission comprising a novel combination and arrangement of gears, fluid pumps, governor, etc., for automatically connecting a driven shaft to a driving shaft and for controlling the speed of the former relative to the latter.

Other objects ofthe invention :are to provide a '5 hydraulic transmission of the character described which will be comparatively simple in construction, strong, durable, highly efficient and reliable in use, compact and which may be manufactured at low cost. Q

All of the foregoing and still further objects andadvantages of the invention will become apparent from a study of the following specification, .taken in connection with the accompanying drawings wherein like, characters of reference desig- 25 nate corresponding parts throughout the several views, and wherein:

Figure l is a view in side elevation of a hydraulic transmission constructed in acordance with the present invention. I

Figure 2 is a viewinrear elevationthereof, the driven shaft being shown in cross section.

Figure 3 is a view in vertical longitudinal section, taken substantially on the line 33 of Figure 2.

Figure 4 is a cross sectional view, taken substantially on the line 4-4 of Fig. 3.

Figure 5 is a vertical sectional view through one of the pump rotors.

Figure 6 is a cross sectional view, taken substanitally on the line 6-6 of Fig. 3.

Referring now to the drawings in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a housing I of suitable metal, said housing including a re- 5 movable back plate 2. The housing I is firmly secured, as at 3, on the crank shaft 4 of an engine 5. It may be well to here state that the housing I constitutes a flywheel.

J ournaled in the housing I and extending rearwardly therefrom through the plate 2 is a driven shaft 6. A bearing 1 is provided for the forward end portion of the driven shaft 6. Firmly secured in the forward end portion of the housing I is a 55 gear 8. Mounted on the gear 8 is a compara- 'tively small gear 9. It will beobserved that the gears 8 and 9 are mounted concentrically relative to-the forwardend portion-of the driven shaft 6. Keyed on the driven shaft 6 in the housing I and spaced rearwardly from the gear 9 is a gear IIl.

Journaled on the driven shaft 6, between the gears 9 and I0, is a metallic wheel or member I I. A suitable bearing I2 is providedfor the wheel II. Journaled on the wheel II and projecting beyond the opposite sides thereof are stub shafts 10 I3. Fixed on the forward end portions of the shafts I3 are planetary gears I4 which are in mesh with the gear 9. Fixed on the rear end portions of the shafts I3 are comparativelysmall gears I 5 which are in mesh'with the gear II].

The wheel II also carries a plurality of fluid pumps which are designated generally by the reference numeral I6. It is here stated that the housing Iis for the reception of a suitable fluid. The pumps I6 include casings II having'mounted therein rotors I8. The shafts I9 'of therotors I8 have fixed thereon gears which arein mesh with the gear 8. As best seen in Fig. 3 of the drawings, the shafts I9 are journaled in the forward ends of the casings H. The rotors I8 are operable in off center chambers 2| in the casings I'I.

' Inlets 22 are provided in the casings H for the entrance of fluid into the chambers H from the housing I.. Back flow of the fluid in the inlets 22 is prevented by check valves 23. The outlets 24 of the pumps I6 are controlled by valves 25 which are rotatably mounted in the casings II. Arms 26 are provided on one end of the valves 25.

Referring now to Fig. 6 of the drawings, it will be observed that the rotors I8 of the pumps I6 have slidably mounted therein vanes 21 which travel on the peripheries of the off center chambers 2I. Springs 28 yieldingly urge the vanes 21 outwardly. The channels in the rotors I8. which accommodate the vanes 21 have communicating therewith vents orducts 29 which assure freedom of movement of said vanes at all times.

The valves 25 are controlled by a governor on the driven shaft 6 which is. designated generally by the reference numeral 30. The governor 38 includes a collar 3I which is splined on the driven shaft 6. Pins 32 on the arms 26 are engaged in the collar 3I for operatively connecting the valves 25 to said collar. The governor further includes a comparatively long sleeve 33 which is spined on the driven shaft 6 and which extends through the plate 2 of the housing I. Weighted toggle links 34 operatively connect the collar 3| to the sleeve 33. A coil spring 35 is mounted on the driven shaft 6 between the collar 3I and the sleeve 33. The reference numeral 36 designates ,a manually actuated lever which is operatively connected to the sleeve 33.

It is thought that the operation of the transmission will be readily apparent from a consideration of the foregoing. Of course, the housing I and the gears 8 and 9 rotate in unison with the shaft 4. When the shaft 4 is stationary the valves 25 are normaly in open position. ever, the construction and arrangement is such that, even when in open position, the valves'25 set up some resistance to the discharge of fluid from the pumps I3. Thus, when the shaft 4 begins to turn the shaft 6 is picked up and caused to turn but at a very low ratio of speed. The gear 8 drives the pumps I6 through the gears 20,

the fluid entering said pumps through the inlets 22 and returning to the housing through the outlets 24. The load 'on the driven shaft 6 causes the pump gears 20 to travel around the gear 8 in a direction opposite to the direction of rotation of said gear 8. Also, the resistance set up by the driven shaft 6 causes the plate or wheel I I to rotate in adirection opposite to that of the applied power. As the shaft 6 picks up speed the valves 25 are progressively closed by the governor 30 thereby restricting the discharge of the fluid from the pumps I6 and consequently retarding the rotors I8. As this operation progresses the plate or wheel I I gradually slows down and then begins to rotate in the same direction as the applied power or motion. When the valves 25 reach fully closed position the pumps I6 are locked and a direct drive from the shaft 4 to the shaft 6 is had. The valves 25 may be manually controlled through the medium of the lever 36. -By operating the lever 36 the sleeve 33 may be moved inwardly or forwardly for compressing the coil spring 35 thereby preventing operation of the collar 3I by the weights of the governor 30 with the result that the valves 25 will be retained in closed or any other desired position regardless of the speed of'rotation-of the shaft 6.

It is believed'that the many advantages of' a hydraulic transmission constructed in accordance with the present invention will be readily understood and although a preferred embodiment of the device is as illustrated and described, it is to be understood that changes in the details of con- I-IoW- struction and in the combination and arrangement of parts may be resorted to which will fall within the scope of the invention as claimed.

What is claimed is:

1. A hydraulic transmission comprising a housing for the reception of a fluid, means connected to the housing for driving same, a driven shaft journaled in the housing, comparatively large and small coaxial gears fixed in one end portion of the housing, agear fixed on the driven shaft, a member journaled on the driven shaft between the first and second named gears, fluid pumps mounted on said member for receiving fluid from the housing and returning said fluid to said housing, gears operatively connecting the pumps to the largest of the first named gears for actuation thereby, stub shafts journaled on said member, gears on one side of the member operatively connecting said stub shafts to the smaller of the first named gears for actuation thereby, gears on the other side of the member operatively connecting the second named gear to said stub shafts, valves for controlling the flow of fluid through the pumps, and means for actuating said valves.

2. A hydraulic transmission comprising a housing for the reception of a fluid, means connected to the housing for driving same, a driven shaft journaled in the housing, gears fixed in the housing, a gear fixed on the driven shaft, a member journaled on the driven shaft, fluid pumps mounted on said member for receiving fluid from the housing and returning said fluid to said housing, means operatively connecting the pumps to one of the first named gears for actuation thereby, stub shafts journaled on said member, gears operatively connecting said stub shafts to the other of the first named gears for actuation thereby, gears operatively connecting the second named gear to said stub shafts, valves for controlling the flowof fluid through the pumps, and means for actuating said valves, said means including a governor comprising a collar and a sleeve splined on the driven shaft, arms on' the valves operatively' engaged with the collar, weighted toggles operatively connecting the collar and sleeve, a coil spring interposed between the collar and sleeve on the driven shaft, and a hand lever operatively connected to the sleeve for compressing the coil spring for yieldingly securing the collar against actuation by the weighted toggles.

JESSE ALBERT SHTQJLTZ. 

